The present invention relates generally to the mountaineering art, and more particularly to a novel irregular, polygonal mountaineering chock for wedging into cracks and openings in rocks to provide protection or support for a climber.
As is well known in the mountaineering art, a climber uses various types of mechanical aids for anchoring and for the attachment of slings and the like to assist in the assent and decent of a wall of rock. These include various types and shapes of pitons, chocks, hooks and bolts.
Although pitons are possibly the most well-known and widely used mechanical aid, the use of chocks has increased and the use of pitons has decreased during recent years, due to the interest in free climbing and because chocks are less likely to scar and flake the rock because they are wedged by hand into position in cracks and piton holes, rather than being driven with a hammer.
Metal chocks for climbing evolved from the use of ordinary machine nuts collected alongside of the Snowdon Railway tracks as climbers hiked up the Clogwgn du'r Arddu. Because these nuts were of uniform or regular hexagonal shape, they could be fitted into a crack in only one attitude. Also, in cracks which bottle-neck or converge over a short distance, this type of uniform shape does not present a problem, but in those instances were the walls of the cracks are substantially parallel, such chocks of uniform or regular hexagonal shape are unsatisfactory.
In recent years, "off-set" hexagonal chocks have been produced in which two opposed faces are shortened an equal amount and the opposed adjacent faces are lengthened an equal amount, to provide a slight acute angle between opposed faces so as to fit between slowly converging walls. Although said "off-set" chocks constituted a considerable improvement over the uniform hexagonal shape, they provided only one size per chock for use with such slowly converging walls.
With the aforementioned limitations and defficiencies of known chocks in mind, it is an object of the present invention to provide a novel irregular, polygonal mountaineering chock which can be used with slowly converging walls or cracks and which provides a plurality of sizes or widths in a single chock for such purpose. More particularly, it is an object to provide such a chock which is of irregular or non-uniform hexagonal shape and which include two widths or sizes in two separate attitudes for use with slowly converging walls or cracks.
Another object is to provide a series of such chocks which will fit in any width of slowly converging crack, from a predetermined minimum width to a predetermined maximum width. More particularly, it is an object to provide a series of such chocks in which the larger end of the wider set of opposed faces of one chock in the series is the same as the smaller end of the narrower set of opposed faces of the next larger chock in the series.
Yet another object is to provide such a series of chocks in which the opposed ends of the chocks are disposed at an acute angle and the chocks are of varying lengths to also provide a range of sizes to accommodate cracks of varying widths.
We have discovered that the above objects and advantages are achieved with a series of irregular, polygonal chocks, preferably hexagonal in shape, having at least two sets of opposed faces with each set converging at an acute angle, preferably ten degrees, and in which the spacing between faces in each set is unequal. In the preferred construction, the larger end of the narrower set of faces is substantially the same size as the smaller end of the wider set of faces. In addition, in the preferred series of chocks of different sizes, the larger end of the wider set of faces of one chock is substantially the same size as the smaller end of the narrower set of faces of the next larger chock.